Effect of high pressure processing (HPP) on the stabilization of plant-based beverages

The global market of plant-based dairy alternatives is growing rapidly. In addition, there is an increasing demand for minimally processed, fresh-like products, with high sensory, nutritional, and health-promoting value. In this context, our study aimed at investigating the potential of High Pressure Processing (HPP) for the stabilization of three vegetable beverages, based on oat, almond and cashew nuts. Unlike beverages based on fruits and vegetables, those obtained from seeds have a pH close to neutrality, which may limit the effectiveness of HPP and the stability of treated products. Three formulations of seed-based drinks, for oat, almond and cashew, respectively, were divided into two batches: one was bottled into 250 mL PET bottles with HDPE caps, which were subjected to a HPP cycle at 600 MPa for 3 min; the other was thermally pasteurized at 82 °C for 30 s and hot-filled into 250 mL glass vases. The stability of HPP-treated and heat-pasteurized samples was monitored through microbiological, sensory, and chemical (antioxidant activity, oxidation degree) parameters, and the shelf life was determined based on microbiological and sensory acceptability limits. Results showed that the HPP process was effective at significantly reducing the initial microbial load of the beverages, at a comparable level with thermal pasteurization. The antioxidant capacity of the beverages, even if different based on the nature of the raw material, maintained stable during 21 days of storage at refrigerated conditions. Microbial counts increased progressively but did not exceed the acceptability limit until at least 21 days. Hence, our comparative shelf life study suggests that, similarly to heat-pasteurized oat, almond and cashew-based drinks, HPP-treated drinks may be assigned a shelf life of 21 days at refrigerated conditions.